Optimized battery assembly venting

ABSTRACT

Systems and methods are provided to vent a battery pack for an electric vehicle. The battery pack comprises a pack housing subdivided by a crossmember. The crossmember defines a multidirectional vent passage configured to allow venting with a first bay and a second bay. A pressure release valve is arranged on the pack housing and configured to release pressure based on the multidirectional vent passage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 63/242,290 filed Sep. 9, 2021, the disclosure of whichis hereby incorporated by reference herein in its entirety.

INTRODUCTION

The present disclosure is directed to optimized vents and venting ofbattery assemblies. The present disclosure is also directed to directingflows of heat or pressure out of battery assemblies to avoid adisruption in the operation of the battery assemblies.

SUMMARY

The present disclosure is directed to systems and methods for ventingheat and pressure generated by battery cells and other conditions withina battery assembly, and more particularly, to systems and methods thatutilize strategically shaped and positioned pressure release valves andother structural features embedded in the walls of the battery assemblyto optimize venting of heat and pressure such that the heat and pressureegress the battery assembly. A battery assembly or battery packincorporating these systems and methods is advantageous in that thepressure release valves, and other structural features, improveefficiency of the operation of the battery cells, reduces environmentalstress caused by pressurized gas, and improves overall packaging of thebattery assembly as the battery assembly is configured to accommodatethe components installed in the environment surrounding the batteryassembly.

The battery assembly may comprise at least one sidewall arranged toencompass in part a plurality of battery cells. In some embodiments, theat least one sidewall may comprise an inner surface comprising an inletopening configured to receive gas generated by the plurality of batterycells, an outer surface comprising an outlet opening configured to ventthe gas, and at least one guiding rib that modifies a trajectory of gas(e.g., at least one of ambient air or pressured gas generated as aresult of heated battery cells changing conditions of the ambient air ina battery assembly) between the inner surface and the outer surface. Thesidewall is advantageous in that it provides an avenue by whichpressurized gas can be vented out of the battery assembly and theprofile of the guiding rib between the inlet and the outlet stabilizethe flow of the pressurized gas and direct the pressurized gas away fromat least one of surrounding components or areas that may be occupied byvehicle occupants.

The battery assembly may additionally incorporate at least one pressurerelease valve, which may be mounted on at least one of the previouslydescribed sidewalls which may be referred to as mounting walls herein.The position of the pressure release valve once installed in thesidewall or mounted to the mounting wall may correspond to a position ofthe previously mentioned outlets in the outer surface. In order toenable optimal venting, the pressure release valve may comprise ahousing configured to be secured to a mounting wall, a first membranepositioned towards a first side of the housing, a second membranepositioned adjacent to the first membrane and positioned towards asecond side of the housing, and a gasket structured to form a continuousseal between the housing and the mounting wall. The membranes and gasketmay be formed out of any material suitable for the temperaturescorresponding to an operational battery assembly such that the materialis able to maintain a watertight seal once the pressure release valve isinstalled. In some embodiments, the membranes may comprise at least oneof a moveable cover, or a rotating enclosure surface. In someembodiments, portions of the housing may be structured to mechanicallydeform (e.g., melt such that at least one membrane falls out of thehousing) when subjected to the conditions corresponding to thermalrunaway resulting from the operation of the battery cells in the batteryassembly. When the portions of the housing mechanically deform, themembranes may fall out of the pressure release valve housing in responseto being exposed to the thermal runaway condition and create an openingin the mounting wall to enable rapid egress of pressurized gas fromwithin the mounting wall, which may be guided by the previouslymentioned guiding rib through the mounting wall to the pressure releasevalve housing.

The battery assembly may be configured for installation and use in avehicle. The walls of the battery assembly may comprise the previouslydiscussed sidewall and may comprise a forward-facing wall configured tobe positioned towards a front of the vehicle, a rear-facing wallconfigured to be positioned towards a rear of the vehicle, a firstplurality of pressure release valves embedded in the forward-facingwall, wherein the first plurality of pressure release valves is arrangedto enable the egress of pressurized gas from between the forward-facingand rear-facing walls, and a second plurality of pressure release valvesembedded in the second wall, wherein the second plurality of pressurerelease valves are arranged to enable the egress of gas from between theforward-facing and rear-facing walls. Each of the first and secondplurality of pressure release valves may comprise the two membranepressure release valves previously discussed. In some embodiments, thetwo membrane pressure release valves are paired with single membranepressure release valves to achieve a target egress rate of thepressurized gas generated by the operation of the battery cells withinthe battery assembly. In some embodiments, there may be a pair of angledtwo membrane pressure release valves on the forward-facing wall with aset of three two membrane pressure release valves embedded in therear-facing wall and positioned level with a flat plane defined by thetop or the bottom of the rear-facing wall, depending on a determinedlocation of an optimal outlet to ensure a maximum target egress rate.For example, each battery assembly may have a variety of wall positionsand features which may affect the path of pressurized gas throughout theassembly. An optimal outlet position for either the first or secondplurality of pressure release valves may balance target stiffness of thewall to survive crash conditions, maximum water ingress allowable forthe battery assembly, and pressurized gas paths within the batteryassembly.

In some embodiments, a battery pack, e.g., for an electric vehicle,includes a pack housing having multiple module bays, e.g., with acrossmember subdividing an interior of the pack housing into twoadjacent module bays. One or both of the module bays may be configuredto support or provide storage for one or more batteries or batterymodules. The crossmember defines a bidirectional or multidirectionalvent passage configured to allow fluid communication between theadjacent module bays. The battery pack may also include a pressurerelease valve positioned at a perimeter of the pack housing.Accordingly, excess pressure from a module bay may pass through thebidirectional vent passage to the one-way vent for venting out of thebattery pack. In some embodiments the crossmember that is arranged withthe sidewall to form a first enclosure separated from a second enclosureby the crossmember. The crossmember comprises a guiding rib thatmodifies a trajectory of gas that transfers from the second enclosure tothe first enclosure.

In some embodiments, the vent passage may be a slot or window in acrossmember, wall, or other structure between the modules or bays. Gasemitted from a battery cell in one module may thereby flow through thebidirectional vent passage to another module, with the gas beingdirected out of the adjacent module from the battery pack (e.g., along,or out of a perimeter of the battery pack). The specific locations ofthe slots, size of the slots, locations and number of vents or pressurerelease valves from the battery pack may be determined to balancestructural support and necessary venting pressure based upon expectedpressure/heat generation by the battery cells.

Bidirectional or multidirectional vent passage(s), in at least someembodiments, may freely allow fluid communication between modules,thereby facilitating relatively free flow of gas discharged from abattery cell along a desired flow path out of the battery pack. In someembodiments, the bidirectional vent passage is open and unobstructed bywiring or other components of the battery pack to provide a direct pathfor fluid communication between the adjacent module bays. Thebidirectional vent passage(s) may also facilitate equalization ofpressure between the module bays. As a result, gas that is dischargedfrom a cell in one module or bay of the battery pack may be routedeffectively to a pressure release valve or one-way pressure releasevalve which provides a vent path out of the battery pack. Vent flowpaths from the modules may be provided to one or more desired locationson the battery pack and may allow consolidation of flow paths fordischarged gas out of the battery pack, as will be discussed furtherbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments. These drawings areprovided to facilitate an understanding of the concepts disclosed hereinand should not be considered limiting of the breadth, scope, orapplicability of these concepts. It should be noted that for clarity andease of illustration, these drawings are not necessarily made to scale.

FIG. 1A depicts a top view of an exemplary battery pack, in accordancewith some embodiments of the disclosure;

FIG. 1B depicts an exploded view of an exemplary battery pack, inaccordance with some embodiments of the disclosure;

FIGS. 2A and 2B each depict a respective cross sectional view of abattery pack sidewall comprising multiple guiding ribs, in accordancewith some embodiments of the disclosure;

FIG. 3 depicts an outer surface of an exemplary battery pack sidewallwith an embedded pressure release value, in accordance with someembodiments of the disclosure;

FIG. 4 depicts a side view of an exemplary battery assembly comprisingat least one vented sidewall arranged to enable rapid egress of at leastone of pressurized or hat gas generated within the battery assembly, inaccordance with some embodiments of the disclosure;

FIG. 5 depicts a cross sectional view of an exemplary sidewallcomprising guiding ribs, in accordance with some embodiments of thedisclosure;

FIG. 6A depicts an example of a battery pack sidewall, with a pressurerelease valve embedded in the battery pack sidewall at an angle,comprising an opening configured to collect moisture, in accordance withsome embodiments of the disclosure;

FIG. 6B depicts an example of a battery pack sidewall, with multiplepressure release valves embedded in the battery pack sidewall, inaccordance with some embodiments of the disclosure;

FIG. 7A depicts a top view of an exemplary dual membrane pressurerelease valve, in accordance with some embodiments of the disclosure;

FIG. 7B depicts a bottom view of an exemplary dual membrane pressurerelease valve, in accordance with some embodiments of the disclosure;

FIG. 8A depicts a top view of an exemplary single membrane pressurerelease valve, in accordance with some embodiments of the disclosure;

FIG. 8B depicts a bottom view of an exemplary single membrane pressurerelease valve, in accordance with some embodiments of the disclosure;

FIGS. 9A and 9B each depict a respective view of an exemplary batterypack sidewall with a pair of angled dual membrane pressure releasevalves in accordance with some embodiments of the disclosure;

FIGS. 10A, 10B, and 10C each depict a respective view of an exemplarybattery assembly with a plurality of pressure release valves, inaccordance with some embodiments of the disclosure;

FIGS. 11A and 11B each depict a respective top view of an exemplarybattery assembly with a plurality of battery module bays, in accordancewith some embodiments of the disclosure;

FIG. 12 depicts an exemplary battery assembly comprised of a pluralityof battery module bays and a plurality of pressure release valves, inaccordance with some embodiments of the disclosure;

FIG. 13 depicts a top view of an exemplary battery assembly with flowpaths indicative of intended flow of at least one of pressurized or hotgas generated based on the operation of the exemplary battery modules,in accordance with some embodiments of the disclosure; and

FIG. 14 is a flowchart depicting an exemplary method of optimizingventing of at least one of pressurized or heated gas generated within abattery assembly, accordance with some embodiments of the disclosure.

DETAILED DESCRIPTION

Methods and systems are provided herein for venting heat and pressuregenerated by battery cells and other conditions within a batteryassembly, and more particularly, to systems and methods that utilizestrategically shaped and positioned pressure release valves and otherstructural features embedded in the walls of the battery assembly tooptimize venting of heat and pressure such that the heat and pressureegress the battery assembly.

FIG. 1A depicts a top view of battery pack 100 (e.g., a batteryassembly, a battery pack assembly, a battery pack system, or anycombination thereof). FIG. 1B depicts an exploded view of battery pack100 with battery pack cover 120 and battery pack base 122, in accordancewith some embodiments of the disclosure. Battery pack 100 may comprisemore or fewer than the components or features depicted in FIGS. 1A and1B. Battery pack 100 may be incorporated into or may incorporate any orall of the components or features depicted in or described in referenceto FIGS. 2A-13 . Additionally, battery pack 100 may be assembled,developed, or manufactured based at least in part on any of the stepsdepicted in or described in reference to FIG. 14 .

As shown in FIG. 1A, battery pack 100 represents an example embodimentof the systems and methods described herein. Battery pack 100 isenclosed by sidewalls 102 a, 102 b, 102 c, and 102 d (collectively, 102)extending about a perimeter of battery pack 100. Battery pack 100encloses battery modules 104 a, 104 b, 104 c, 104 d, 104 e, 104 f, 104g, 104 h, and 104 i (collectively, 104), which collectively providepower to an apparatus or system requiring electrical power for operation(e.g., an electric vehicle powertrain system configured to enablemovement of the electric vehicle). Battery modules 104 are enclosedwithin module bays 105 a, 105 b, 105 c, 105 d, and 105 e (collectively,105), which are defined by sidewalls 102 and crossmembers 106 a, 106 b,106 c, and 106 d (collectively, 106). Collectively, sidewalls 102 andcrossmembers 106 form housing 124. Each bay of bays 105 is configured toaccommodate at least one of battery modules 104, and as shown in FIG. 1Abay 105 a is configured to accommodate a single one of battery modules104 and the each of the remaining bays 105 b-e is configured toaccommodate two of battery modules 104. In some embodiments, any numberof modules 104 may be positioned in any of bays 105 (e.g., depending onthe dimensions of at least one of housing 124, any of bays 105, orbattery modules 104). Crossmembers 106 each extend laterally alongbattery pack 100 between sidewalls 102 c and 102 d.

Battery pack 100 may be substantially sealed such that fluid flow (e.g.,at least one of pressurized or heated gas into and out of the enclosuredefined by sidewalls 102) is limited to specific venting flow paths.Venting flow paths, as shown in FIG. 1A, are provided by pressurerelease valves 108, plug valves 110, and deformable pressure releasevalves 112. Pressure release valves 108, 110, and 112 are generallyconfigured to handle different levels of pressure/flow from battery pack100 to an external environment surrounding housing 124 of battery pack100. In some embodiments, plug valves 110 may facilitate relativelylow-pressure flows to and from battery pack 100, which may occur due toat least one of thermal expansion or contraction of gas within batterypack 100 corresponding to the operation of battery modules 104. Plugvalves 110 may be a generally solid plug of permeable materialconfigured to permit a maximum level of flow that is relatively low,consistent with thermal expansion/contraction of battery pack 100.

Pressure release valves 108 are configured to facilitate one-way flowout of battery pack 100 in response to relatively greater thermal orpressure flows than ambient conditions within battery pack 100 prior tooperation of battery modules 104 within module bays 105. Pressurerelease valves 108 may each include moveable pressure release valvemembers, such as an umbrella valve or umbrella membrane. In someembodiments, the membranes may comprise at least one of a moveablecover, or a rotating enclosure surface. Each of the moveable pressurerelease valve members is configured to provide one-way flow out ofbattery pack 100, while sealing against intrusion of water or othercontaminants. Battery pack 100 includes multiple pressure release valves108, with two provided in front sidewall 102 a and three located in rearsidewall 102 b.

In contrast to plug valves 110 and pressure release valves 108,deformable pressure release valves 112 may facilitate a relativelygreater flow of at least one of pressurized or heated gas from withinhousing 124 (e.g., due to a sudden or extreme thermal eventcorresponding to at least one battery cell of at least one of batterymodules 104). Deformable pressure release valves 112 may include adeformable disc or other structure that is configured to mechanicallydeform (e.g., break, melt, or otherwise disintegrate such thatdeformable pressure release valves 112 form an opening in a sidewall ofhousing 124) in response to a pressure or temperature above apredetermined amount (e.g., as may be characteristic of a thermal eventof battery cells in battery pack 100 based on damage to or operation ofbattery modules 104). Exemplary embodiment of pressure release valve 108is illustrated in FIGS. 9A and 9B. Pressure is allowed to vent frombattery pack 100 (e.g., as shown in FIG. 14 ). Additionally, flow in thereverse direction, (e.g., into battery pack 100) may be generallyprevented by a perimeter seal arranged along at least one of an innersurface or an outer surface of sidewalls 102 (no shown). The perimeterseal may have a preload against a corresponding seal surface, which isgenerally defined by a flexibility of the perimeter seal (e.g., anability to elastically deform and retain an original shape despiteexperiencing strain within an elastic range of the material comprisingthe perimeter seal) and an insertion load of pressure release valves 108resulting in a seal between a perimeter of pressure release valves 108and openings in sidewalls 102 configured to receive pressure releasevalves 108.

Battery pack 100 may be configured to vent from within housing 124(e.g., based on at least one of pressurized or heated gas generatedwithin module bays 105 in response to operation of battery modules 104)to the external environment surrounding housing 124 in response todifferent levels or thresholds of internal pressure or heatcorresponding to the different fluid flow paths provided by valves 108,110, and 112, respectively. In one example, plug valves 110 may beconfigured to vent an internal pack pressure not exceeding a firstpressure threshold (e.g., 5 kPa of pressure within the battery pack 100)which may fall within a range of pressure created by thermal expansionof air contained within battery pack 100. Plug valves 110 may alsopermit ingress of air in response to thermal contraction of air withinbattery pack 100. Relatively higher levels of pressure (e.g., from thefirst pressure threshold to a second or higher pressure threshold), maybe vented from battery pack 100 via pressure release valves 108 inresponse to venting of one or more battery modules 104, higher levels ofheat output of battery modules 104 based on the operating conditions ofbattery modules 104, or other conditions creating additional pressurewithin battery pack 100. In some embodiments, the pressure thresholds ofthe disclosure refer to pressure differentials between a space withinthe battery pack enclosing a battery module or a battery and a spaceexternal to the battery pack.

Accordingly, continuing with the example first pressure thresholdintroduced above, internal pressures of 5 kPa to 10 kPa within batterypack 100 may be vented by at least one of pressure release valves 108.An internal pack pressure reaching a higher pressure threshold than canbe serviced by plug valves 110 may be vented via pressure release valves108. Further, even higher levels of at least one of pressure or heatexceeding the second threshold level or pressure levels generallyserviceable by pressure release valves 108 (e.g., above 10 kPa) may bevented from battery pack 100 by deformable pressure release valves 112.In an example, a sudden onset of internal pressure may quickly reach thefirst pressure threshold pressure (e.g., 5 kPa) causing pressure releasevalves 108 to begin venting. If pressure continues to rise above levelsserviceable by pressure release valves 108 (e.g., above 10 kPa or above50 kPa), one or more of deformable pressure release valves 112 maymechanically deform, allowing further release of the internal pressureby creating an uncovered through opening in at least one of sidewalls102 that enables egress from within module bays 105 to the environmentsurrounding housing 124. Each of these outputs may propagate throughoutbattery pack 100, as described further below. In some examples, apressure buildup or flow exceeding a predetermined amount (e.g., above10 kPa) may generate a warning for service of battery pack 100. Forexample, control circuitry may be arranged within battery pack 100 whichcomprises sensors (e.g., a water sensor configured to detect standingwater within the battery pack assembly, a temperature sensor, a voltagesensor, and a pressure sensor). These sensors may be configured toprovide at least one of data or instructions to generate at least onewarning to a vehicle operator, a vehicle controller, or any combinationthereof.

Battery pack 100 is substantially sealed against egress of environmentalfluids or materials, apart from the fluid flows permitted by thepressure release valves 108, 110, and 112 to address increases of atleast one of pressure or temperature within sidewalls 102. Sidewalls 102and crossmembers 106 generally may create module bays 105 (e.g.,individual enclosures within housing 124) around at least one of batterymodules 104 (e.g., in some embodiments two of battery modules 104 asshown in FIG. 1A). While nine of battery modules 104 are illustratedbeing distributed amongst module bays 105, any number of modules 104 ormodule bays 105 may be employed (e.g., contingent on a desired poweroutput of battery pack 100 or at least one of a weight or spaceconstraint associated with the environment surrounding housing 124). Anyor all of module bays 105 may contain any number of modules 104 that isconvenient. Battery modules 104 a-i may be comprised of a plurality ofbattery cells that are interconnected to generate an amount ofelectrical energy to be provided to a larger vehicle system (e.g., viaat least one of a bus bar or at least one terminal connection). Batterymodules 104 a-i may be arranged vertically, horizontally, or may bestacked over each other depending on the available packing space of thestructure for which the battery pack 100 is configured to provideelectrical power. In some embodiments, battery modules 104 within one ormore of module bays 105, and in some cases each of module bays 105, arepositioned in a two-layer stack of battery cells. More specifically, asillustrated in FIG. 13 , a lower layer of battery modules may bepositioned beneath an upper layer of battery modules. In someembodiments, a cooling apparatus or layer may be positioned between.

Module bays 105 of battery pack 100 may permit fluid communication viaone or more of vent passages 118 to permit flow of at least one ofpressurized or heated fluid (e.g., gas or liquid) to at least one ofpressure release valves 108, 110, or 112 for venting. Vent passages 118may be bidirectional (e.g., enabling ingress and egress of at least oneof heated or pressurized fluid between two of module bays 105) ormultidirectional (e.g., enabling at least two of ingress, egress, orsome other transitory propagation of at least one of heated orpressurized fluid between at least two of module bays 105 or between atleast two of battery modules 104, based on either a lateral or verticalarrangement of the at least two of battery modules 104). Each of ventpassages 118 are provided in laterally extending crossmembers 106 ofbattery pack 100. Additionally, the forwardmost module bay 105 a mayvent to the external environment surrounding housing 124 via at leastone of pressure release valves 108, and rearward most module bay 105 emay vent to the external environment surrounding housing 124 via atleast one embedded iteration of pressure release valves 108.

Vent passages 118 are shown in FIG. 1A as extending between differentcombinations of module bays 104 and may generally freely allow fluidflow. In some embodiments, vent passages 118 may also be configured toenable passage of heated or pressurized fluid between verticallyarranged battery modules 104 (e.g., as shown in FIG. 13 ). Accordingly,a thermal event or cell venting event in any of module bays 105 iscommunicated to an adjacent module bay of module bays 105. Further, tothe extent this may cause a buildup of pressure within module bays 105collectively, resulting in pressure release valves 108 collectivelyventing at least one of pressurized or heated fluid (e.g., gas, vapor,or liquid) to the external environment surrounding housing 124.Crossmembers 106 may provide structural support to at least one ofbattery pack 100 or a vehicle into which battery pack 100 is installed.Accordingly, vent passages 118 may generally facilitate a balancebetween the additional structural strength of battery pack 100 providedby crossmembers 106, while also facilitating an adequate vent flow outof battery pack 100. Vent passages 118 are positioned to facilitate ventflows along a floor structure (e.g., battery pack base 122 of FIG. 1B).At least some battery cells comprising battery modules 104 may bepositioned such that venting from the cells tends to flow toward thefloor structure. As such, venting from these cells may be facilitated byvent passages 118. At the same time, upper cells within the module mayvent upwards within the module bays 104 toward a battery pack top orcover (e.g., battery pack cover 120).

FIG. 1B depicts an exploded view of battery pack 100 comprising batterypack cover 120 and battery pack base 122. Battery pack base 122 providesa bottom support or surface of battery pack 100, upon which at least oneof battery modules 104, various sensors, vehicle system interfaces andthe like may be supported or arranged. Battery pack cover 120 isconfigured to enclose module bays 105 from above. Battery pack cover 120may be positioned over mica sheets which would aid in managing heat andpressurized gas generated by the operation of battery cells (e.g.,comprising battery modules 104 of FIG. 1A) arranged in each of modulebays 105. Each of battery pack cover 120 and battery pack base 122 maybe fixedly attached to at least a portion or at least one of any or allof sidewalls 102 and crossmembers 106. In some embodiments, at least onepressure release valve may be arranged in a forward facing surface ofsidewalls 102 while at least one pressure release valve may be arrangedin at least one mounting location in a rear facing surface of sidewalls102. In some embodiments, battery pack 100 may comprise at least oneadditional sidewall 102, that is not forward or rear facing, without atleast one pressure release valve when at least one of a forward-facingwall of sidewalls 102 or a rear-facing wall of sidewalls 102 compriseenough deformable pressure release valves or plug valves to enabletarget pressurized or heated fluid egress rates.

Between each of module bays 105 is at least one of vent passages 118,which may be positioned towards or at the bottom of each of a pluralityof crossmembers 106. The position of each of vent passages 118 in eachrespective crossmember of crossmembers 106 may depend on an optimal flowpath for at least one of hot or pressurized fluid generated by theoperation of battery modules 104, as determined based on operatingparameters of a particular embodiment of battery pack 100. In someembodiments, at least one of vent passages 118 is unobstructed and atleast one other of vent passages 118 is at least partially obstructed byvarious battery assembly components (e.g., coolant lines). In someembodiments, an inlet of at least one of vent passage 118, enabling theegress of gas out of one of module bays 105, is positioned higher thanan outlet of the at least one vent passage, where a vent housing may beinstalled (e.g., a pressure release valve). In some embodiments, theinlet may be positioned lower than the outlet.

At least one of sidewalls 102 or crossmembers 106 may comprise anextruded material. At least one inlet or at least one outlet maycomprise machined cutouts of the extruded material (e.g., to accommodateat least one of at least one vent passage118 or at least one pressurerelease valve). Battery pack 100 may be formed by a method ofmanufacturing comprising extruding a rigid material to form at least onesidewall comprising an inner surface, an outer surface, and at least oneguiding rib. The guiding rib may comprise a first end abutted to theinner surface, a second end abutted to the outer surface, and a profilestructured to modify the trajectory of gas generated from inside thebattery assembly. A center of the guiding rib is proximate to a verticalcenter of the sidewall such that the inlet and outlet maintain a targetstiffness level of the inner surface and the outer surface. Once the atleast one sidewall is formed, the at least one sidewall is arranged toform an enclosure at least partially. Within the enclosure, at least onebattery module comprising a plurality of battery cells may be arranged.The sidewall may comprise a plurality of inlets and a correspondingplurality of outlets, wherein each of the plurality of inlets andcorresponding outlets are adjacent to each other, to accommodate hot gasgenerated by a plurality of battery modules arranged in the enclosure.The described components and method of manufacturing may also beutilized to produce a battery pack, comprising at least one batterymodule comprising plurality of battery cells, and at least one sidewallarranged to encompass in part the battery module. The at least onesidewall may comprise an inner surface comprising an inlet openingconfigured to receive gas generated by the plurality of battery cells,an outer surface comprising an outlet opening configured to vent thegas, and a guiding rib that modifies a trajectory of gas between theinner surface and the outer surface.

FIG. 2A depicts a cross sectional view of sidewall 200A comprised ofangled guiding ribs 202A formed by material with a straight surfaceprofile. FIG. 2B depicts a cross sectional view of sidewall 200Bcomprising curved guiding ribs 202B, in accordance with some embodimentsof the disclosure. Each of sidewalls 200A and 200B may comprise more orfewer than the components or features depicted in FIGS. 2A and 2B. Eachof sidewalls 200A and 200B may be incorporated into or may incorporateany or all of the components or features depicted in or described inreference to FIGS. 1 and 3-13 . Additionally, each of sidewalls 200A and200B may be assembled, developed, or manufactured based at least in parton any of the steps depicted in or described in reference to FIG. 14 .

Sidewall 200A corresponds to any or all of sidewalls 102 of FIG. 1 , andmay be arranged to form housing 124. In some embodiments, sidewall 200Amay be positioned below a vehicle occupant zone or may be positioned toavoid venting at least one of pressurized or hot fluid from inside abattery pack onto components surrounding the battery pack (e.g., asshown in FIGS. 11A, 11B, and 11C). Sidewall 200A comprises inner surface204, outer surface 206, and angled guiding ribs 202A. Inner surface 204is arranged and configured to receive at least one of hot or pressurizedgas from inside a battery enclosure (e.g., module bays 105 of FIG. 1 )as generated by the operation of at least one battery module (e.g.,battery modules 104 of FIG. 1 ). Outer surface 206 comprises opening 208configured to receive pressure release valve housing 210 affixed toouter surface 206 by interfacing with opening 208. Pressure releasevalve housing 210 when interfacing with opening 208 comprises outlet214. Outlet 214 is configured to enable the egress of at least one ofpressurized or hot gas after the pressurized or hot gas progressesthrough inlet 216 in response to a pressure differential between anenvironment in front of inlet 216 (e.g., corresponding to at least oneof module bays 105 of FIG. 1 ) and an environment outside of outlet 214(e.g., a vehicle underbody). For example, the environment in front ofinlet 216 may correspond to an atmospheric pressure that is below apressure to the right of inner surface 204 of FIG. 2 . Between outersurface 206 and inner surface 204 are guiding ribs 202A, which provideupper and lower boundaries for guiding at least one of hot orpressurized fluid (e.g., gas, vapor, or liquid) from inlet 216 throughoutlet 214. In some embodiments, at least one of guiding ribs 202Acomprises a straight profile (e.g., as shown in FIG. 2A) with first end218 affixed to a surface that faces outlet 214. First end 218 isarranged vertically higher than second end 220, which is affixed asurface that faces inlet 216. The steepness of at least one of guidingribs 202A and the profile prevents restriction of flow of at least oneof hot or pressurized fluid by preventing turbulence in the flow of thehot or pressurized fluid and enables the hot or pressurized fluid tofollow exit trajectory 222 instead of exit trajectory 224. Exittrajectory 222 prevents the egress of the hot or pressurized fluidtowards a portion of the environment external to outer surface 206 thatcontains components and the like that cannot withstand exposure to thehot or pressurized gas (e.g., as shown in FIGS. 11A, 11B and 11C). Exittrajectory 224 corresponds to an exit trajectory of the hot orpressurized fluid without the guiding ribs, which would result in thecollection of the hot or pressurized fluid between inner surface 204 andouter surface 206. Additionally, exist trajectory 224 corresponds to afluid flow that may result in exposure of components and the likeexternal to outer surface 206 that should not be exposed to the hot orpressurized fluid.

Sidewall 200B comprises the components of sidewall 200A without guidingribs 202A with a straight profile. Instead, sidewall 200B comprisescurved guiding ribs 202B. The curved profile of guiding ribs 202B beginswith first end 218 affixed to a surface that faces outlet 214. First end218 is arranged vertically higher than second end 220, which is affixeda surface that faces inlet 216. The curved profile of guiding ribs 202Bprevents restriction of flow of at least one of hot or pressurized fluidby preventing turbulence in the flow of the hot gas while guiding theexit trajectory of the hot or pressurized fluid away from certain areasexternal to the battery assembly (e.g., surrounding components as shownin FIGS. 11A, 11B, and 11C). The curve of the profile may be determinedbased on turbulence and restriction of flow target values for at leastone of hot or pressurized fluid generated by the operation of batterymodules (e.g., battery modules 104 of FIG. 1 ) within an enclosure(e.g., module bays 105 of FIG. 1 ). The change of direction of the fluidflow trajectory as defined by the curved profile of curved guiding ribs202B from inlet 216 to outlet 214 enables transition of vectors definingthe fluid flow without creating turbulence in the fluid flow. In someembodiments, either or both of sidewalls 200A or 200B comprises extrudedmaterial, wherein inlet 216 and outlet 214 comprise machined cutouts ofthe extruded material. In some embodiments, sidewalls 200A and 200B haveat least one guiding rib, wherein a center of the guiding rib isproximate to a vertical center of inner surface 204 and outer surface206, thereby maintaining a target stiffness level for either or both ofsidewalls 200A and 200B. In some embodiments, at least one of sidewall200A or 200B comprises a plurality of inlets 216 and outlets 214,wherein each of the plurality of inlets 216 and outlets 214 are adjacentto each other in at least one of sidewall 200A or 200B (e.g., as shownin FIG. 3 ).

FIG. 3 depicts sidewall assembly 300 comprising dual membrane pressurerelease valve 700 of FIGS. 7A and 7B, outlets 214 of FIG. 2 , and curvedguiding ribs 202B of FIG. 2 , in accordance with some embodiments of thedisclosure. Sidewall assembly 300 may comprise more or fewer than thecomponents or features depicted in FIG. 3 . Sidewall assembly 300 may beincorporated into or may incorporate any or all of the components orfeatures depicted in or described in reference to FIGS. 1-2B and 4-13 .Additionally, sidewall assembly 300 may be assembled, developed, ormanufactured based at least in part on any of the steps depicted in ordescribed in reference to FIG. 14 .

Sidewall assembly 300 comprises a plurality of outlets 214, with dualmembrane pressure release valve 700 of FIGS. 7A and 7B populating one ofthe plurality of outlets 214. Exposed outlets 214 are shown forillustration and may be covered by additional dual membrane pressurerelease valves or other valves described herein. In some embodiments,all of the pressure release valves may comprise a single large membranein place of the two separate membranes as shown in FIGS. 9A and 9B.Sidewall assembly 300 also comprises a plurality of curved guiding ribs202B of FIG. 2 . In some embodiments, sidewall assembly 300 comprisesguiding ribs 202A of FIG. 2A. In some embodiments, a combination ofguiding ribs 202A and curved guiding ribs 202B may be utilized. Sidewallassembly 300 may be arranged or positioned anywhere around housing 124of FIG. 1 by being arranged where any or all of sidewalls 102 aredepicted in FIG. 1 . Sidewall assembly 300 may at least partially format least one of module bays 105 of FIG. 1 . Dual membrane pressurerelease valve 700 may be structured to increase a material stiffness ofsidewall assembly 300, considering the material stiffness of sidewallassembly 300 may be reduced by machining exposed outlets 214. In someembodiments, at least one of plurality of dual membrane pressure releasevalves 700 may populated each of exposed outlets 214. Each of theplurality of dual membrane pressure release valves 700 may correspond toa target stiffness value for the wall by being comprised of a housingthat, when arranged within one of exposed outlets 214, increases thematerial stiffness of sidewall assembly 300 to a target stiffness value(e.g., the yield or ultimate strength of sidewall assembly 300 increasedwhen at least one of exposed outlets 214 is populated by one of dualmembrane pressure release valves 700). For example, sidewall 300 withexposed outlets 214 may have a reduction of at least 15% in the materialstiffness of material comprising sidewall 300. When exposed outlets 214are populated by dual membrane pressure release valves 700, the materialstiffness of sidewall 300 may only be reduced by 5%, may return to aninitial material stiffness, or may exceed the material stiffness ofsidewall 300 before exposed outlets 214 are machined.

FIG. 4 depicts view 400 with sidewall assembly 300 of FIG. 3 ,comprising at least one pressure release valve configured to enablerapid egress of at least one of pressurized or hot fluid generatedwithin a battery assembly enclosed at least partially by sidewallassembly 300, arranged to vent the pressurized or hot fluid towardstarget egress area 402 and away from protected area 404, in accordancewith some embodiments of the disclosure. View 400 may comprise more orfewer than the components or features depicted in FIG. 4 . View 400 maybe incorporated into or may incorporate any or all of the components orfeatures depicted in or described in reference to FIGS. 1-3 and 5-13 .Additionally, the components depicted in or described in reference toview 400 may be assembled, developed, or manufactured based at least inpart on any of the steps depicted in or described in reference to FIG.14 .

As shown in view 400, sidewall assembly 300 comprises a plurality ofoutlets 214 of FIG. 2 . Exit trajectory 222 corresponds to the exittrajectory of at least one of pressurized or hot fluid, as shown in anddescribed in reference to FIG. 2 . Exit trajectory 222 is shown as beingdirected towards target expulsion area 402. Target expulsion area 402corresponds to an area which outlets 214 guides the at least one ofpressurized or hot fluid towards without exposing components or areasaround sidewall assembly 300 (e.g., areas around housing 124 of FIG. 1 )that are not configured or structured to withstand the hot orpressurized fluid. For example, FIGS. 11A, 11B, and 11C each providestructural areas and components that may be arranged out of targetexpulsion area 402 to avoid exposure to the expelled pressurized or hotfluid. Sidewall assembly 300 is positioned or arranged below protectedarea 404.

Protected area 404 may correspond to a vehicle body, a vehicle frame, anoccupant area, a cargo area, or any suitable form of enclosure,structural component, or assembly that is configured to interface orcouple with a battery pack or battery assembly comprised of sidewallassembly 300. View 400 includes vehicle assembly 408, which is inclusiveof all the elements of FIG. 4 . Protected area 404 is not arranged orconfigured to receive any portion of exit trajectory 222 as protectedarea 404 is arranged above top lateral edge 406. Exit trajectory 222 maybe enabled by at least one of a pressure release valve (e.g., a singleor dual membrane valve as shown in FIGS. 7A-9B) or at least one guidingrib connecting surfaces forming sidewall assembly 300 (e.g., as shown inFIGS. 2A-3 ). Exit trajectory 222 enables the expulsion of at least oneof pressurized or hot fluid downward award from top lateral edge 406.Additional single or dual membrane pressure release valves may bepositioned in sidewall assembly 300 or a battery pack assembly comprisedof housing 124 of FIG. 1 to optimize the amount of hot or pressurizedfluid expelled during any given event which causes a buildup ofpressurized gas within the battery pack assembly.

FIG. 5 depicts a cross sectional view of sidewall assembly 500, inaccordance with some embodiments of the disclosure. Sidewall assembly500 may comprise more or fewer than the components or features depictedin FIG. 5 . Sidewall assembly 500 may be incorporated into or mayincorporate any or all of the components or features depicted in ordescribed in reference to FIGS. 1-4 and 6A-13 . Additionally, sidewallassembly 500 may be assembled, developed, or manufactured based at leastin part on any of the steps depicted in or described in reference toFIG. 14 .

Sidewall assembly 500 comprises first guiding rib 506A, wherein firstend 508A of first guiding rib 506A is positioned towards orsubstantially at top edge 510A of the opening of inlet 216. Second end508B of first guiding rib 506A is positioned towards or substantially attop edge 510B of the opening of outlet 214. Sidewall assembly 500 alsocomprises second guiding rib 506B, wherein first end 512A of secondguiding rib 506B is positioned towards or substantially at bottom edge514A of the opening of inlet 216. Second end 512B of second guiding rib506B is positioned towards or substantially at bottom edge 514B of theopening of outlet 214. Sidewall assembly further comprises third guidingrib 506C. Third guiding rib 506C is positioned or arranged verticallybetween first guiding rib 506A and second guiding rib 506B. Thirdguiding rib 506C forms first channel 516A with first guiding rib 506Aand second channel 516B with second guiding rib 506B, wherein each offirst channel 516A and second channel 516B provide an open egress pathfor at least one of hot or pressurized fluid with a trajectory flowingtowards an outer surface of inlet 216 and towards an inner surface ofoutlet 214.

Third guiding rib 506C is comprised of first recess 518A arrangedtowards the opening of inlet 216, wherein first recess 518A isconfigured to reduce turbulence corresponding to the trajectory of gas.First recess 518A may be at least one of configured to enable gas flowat target turbulence levels or incorporated for ease of manufacturing orassembly. By reducing inlet area with the recess, inlet 216 isconfigured to reduce a likelihood of restricted flow and improveefficiency of flow when a rapid egress of at least one of hot orpressurized fluid is required to maintain function of a batteryassembly. The recess may also reduce the surface across which the flowof hot gas travels and also reduces the likelihood of turbulence inorder to improve the efficiency of the egress of the at least one of hotor pressurized fluid. Third guiding rib 506C also is comprised of secondrecess 518B arranged towards the opening of outlet 214, wherein secondrecess 518B is configured to accommodate a rear portion of a valveaffixed to the outer wall (e.g., membrane 504 in vent housing 210).Second recess 518B is arranged such that neither a surface nor edge ofmaterial forming second recess 518B contacts a rear portion of thepressure release valve comprising membrane 504. In some embodiments, anaccommodating recess is not formed in third guiding rib 506C towardsinlet 216.

Affixed an outer surface of sidewall assembly 500, corresponding to anouter surface of outlet 214, is vent housing 210. Vent housing 210 maycomprise a membrane pressure release valve configured to deform whenexposed to hot gas corresponding to a thermal runaway condition suchthat membrane 504 of the pressure release valve comprising vent housing210 and membrane 504 are mechanically displaced (e.g., mechanicallyreleasing a seal formed between the membrane and the housing), creatinga large opening at outlet 214 for the rapid egress of at least one ofhot or pressurized gas. Embedded in a groove of vent housing 210 is ventgasket 502. Vent gasket 502 is configured to mechanically seal against asurface of sidewall assembly 500 such that at least one of hot orpressurized gas is directed to outlet opening 514B. Additionally, ventgasket 502 is configured to prevent moisture from entering sidewallassembly 500 through vent housing 210.

FIG. 6A depicts first sidewall 600A and FIG. 6B depicts second sidewall600B, in accordance with some embodiments of the disclosure. Firstsidewall 600A and second sidewall 600B may comprise more or fewer thanthe components or features depicted in FIGS. 6A and 6B. First sidewall600A and second sidewall 600B may be incorporated into or mayincorporate any or all of the components or features depicted in ordescribed in reference to FIGS. 1-5 and 7A-13 . Additionally, at leastone of first sidewall 600A or second sidewall 600B may be assembled,developed, or manufactured based at least in part on any of the stepsdepicted in or described in reference to FIG. 14 .

First sidewall 600A is comprised of angled vent housing 602 that isembedded (e.g., affixed) in an outer surface of first sidewall 600A. Itwill be understood that vent housing 602 is angled with respect to theouter surface (e.g., rotated about an axis normal to the outer surface),such that one side of vent housing 602 is lower than the other side ofvent housing 602. First sidewall 600A comprises a pair of surfaces, theouter surface configured to receive angled vent housing 602 and an innersurface comprised of inlet 214. Between the outer surface and the innersurface is internal cavity 604 for collecting moisture such that it doesnot enter an enclosure partially formed by first sidewall 6001 (e.g.,module bays 105 of FIG. 1 ). Collected moisture 606 corresponds tofluids that was able to enter between the inner and outer surfaces offirst sidewall 600A. Preferably, collected moisture 606 should have avolume substantially equivalent to zero (e.g., no moisture enters firstsidewall 600A or second sidewall 600B). However, it may be understoodthat during operation of a battery pack comprised of at least one offirst sidewall 600A or second sidewall 600B various sealing interfacesmay have imperfect sealing function and moisture may collect at variousinterfaces throughout the battery pack. As a result, the battery packcomprised of at least one of first sidewall 600A or second sidewall 600Bmay be configured to remain operable despite moisture collecting withinthe assembly. For example, a maximum level of allowable moisture (e.g.,a maximum fluid ingress amount) in a battery enclosure may be 1.5 mm.Internal cavity 604 may be structured such that internal cavity 604 canstore enough moisture collected from the environment around the batterypack or during operation of the battery pack that 1.5 mm of moisture isprevented from collecting in the enclosure at least partially formed byat least one of first sidewall 600A and second sidewall 600B (e.g., theheight of the inner surface and outer surface forming the internalenclosure is configured such that a volume of water corresponding to atleast 1.5 mm throughout the enclosure can be stored in the internalcavity). Second sidewall 600B includes openings in an outer surface forthe installation horizontally aligned vent housing 608. Second sidewall600B also comprises inlets 214, each corresponding to at least one ofvent housings 608. First sidewall 600A may be arranged such that anoutlet of angled vent housing 602A faces a forward portion of a vehicleassembly comprised of a battery pack comprised of first sidewall 600A.Second sidewall 600B may be arranged such that the outlets ofhorizontally aligned vent housings 608 face a rear portion of a vehicleassembly comprised of a battery pack comprised of second sidewall 600B.It will be understood that there may be more or fewer of at least one ofventing openings or venting housings, depending on the desired egressrates of at least one of pressurized or heated fluid generated throughthe operation of a plurality of battery cells operating proximate to thedepicted sidewalls (e.g., within module bays 105 of FIG. 1 ). Theventing housings may comprise dual or single membrane pressure releasevalves, depending on the desired preload-sealing criteria of aparticular battery assembly.

FIG. 7A depicts outer surface 702A of dual membrane pressure releasevalve 700 and FIG. 7B depicts inner surface 702B of dual membranepressure release valve 700, in accordance with some embodiments of thedisclosure. Dual membrane pressure release valve 700 may comprise moreor fewer than the components or features depicted in FIGS. 7A and 7B.Dual membrane pressure release valve 700 may be incorporated into or mayincorporate any or all of the components or features depicted in ordescribed in reference to FIGS. 1-6 and 8A-13 . Additionally, dualmembrane pressure release valve 700 may be assembled, developed, ormanufactured based at least in part on any of the steps depicted in ordescribed in reference to FIG. 14 .

Dual membrane pressure release valve 700 comprises housing 704 withrigid mounts 706. In some embodiments, rigid mounts 706 comprisefeatures that extend from housing 704 and may interface with or at leastpartially comprise rigid mounts 706 such that dual membrane pressurerelease valve 700 may receive or be configured to interface withexternal deflectors. For example, each of rigid mounts 706 maycorresponds to or may be comprised of extensions configured to form asnug fit interface (e.g., based on a compression fit specification thatrequires a press in load to be 50% or less of a pull out load once theinterface is established by pressing in each of rigid mounts 706 into anopening in the sidewall) with an opening in the sidewall correspondingto the outline of housing 704 that is inclusive of the extensions orrigid mounts. Each of rigid mounts 706 incorporate at least one of rigidinserts 708 to reduce a transfer of torque or load from a fastenerconfigured to interface with each of rigid mounts 706 to other featuresof housing 704 (e.g., to prevent mechanical deformation of housing 704which may compromise sealing around dual membrane pressure release valve700 by resisting a compression force generated by applying aninstallation torque to the fastener from transferring to the rigidmount). In some embodiments, rigid inserts 708 may be comprised of ametal material while housing 704 is comprised of a plastic material witha lower material strength than the metal material used for rigid inserts708. Extending features 710 encompass each of membranes 712 to increasestiffness of housing 704 in order to prevent mechanical deformation(e.g., elastic or plastic) of housing 704.

Each of membranes 712 comprise an area corresponding to a target preloadrequired to translate membranes 712 to enable the egress of at least oneof hot or pressurized fluid from behind each of membranes 712 (e.g., asgenerated by the operation of battery modules in module bays 105 of FIG.1 ). Membranes 712 are configured to create a seal against respectiveopenings in housing 704. The openings correspond to an area formed atleast partially by deformable struts 722. The target preload of each ofmembranes 712 may also correspond to target sealing levels to preventthe ingress of moisture behind the membranes (e.g., reducing an amountof fluid collected in FIG. 6 ). For example, the total area of membranes712 may correspond to a maximum flow rate of the egress of at least oneof pressured or heated fluid to prevent a buildup of pressure or heat ina battery pack comprised of sidewalls with at least one of dual membranepressure release valve 700 embedded in an outer surface of at least oneof the sidewalls. In order to balance the egress of hot gas against theneed to prevent a threshold amount of moisture from entering the batterypack, the total area of membranes 712 is divided between two separatemembrane structures such that each of membranes 712 corresponds to ahigh enough sealing preload to prevent the ingress of moisture withoutexceed a sealing preload that would prevent rapid egress of at least oneof pressurized or heated fluid. The sealing preload corresponds to aforce required to translate at least one of membranes 712 away fromhousing 704 to create an opening outer surface 702A. Forces acting on abattery pack comprised of dual membrane pressure release valve 700 mayaffect the integrity of a seal formed by each of membranes 712. Forexample, various forms of excitation to the surfaces of the battery packcaused by pressure differentials, vibrating mediums, or rapid changes indirection may comprise a seal by disrupting the contact surfaces alongeach of membranes 712. As a result, the battery pack may be configuredto remain operational with some fluid ingress that is below a thresholdfluid ingress that may affect operation of the battery pack.

Inner surface 702B is arranged to face opposite of outer surface 702A.As shown, rigid mounts 706 are arranged around the periphery of housing704. Each of rigid mounts 706 are comprised of reinforcement vanes 714which are structure to increase the material stiffness of each of rigidmounts 706, thereby reducing a risk of mechanical deformation ordeflection during installation or articulation of membranes 712.Reinforcement valves 714 are arranged radially around openings in eachof rigid mounts 708 to prevent deflection or deformation of rigid mounts708. Rigid mounts 708 may comprise a first rigid mount arranged toprotrude from a top side of housing 702 and further arranged laterallybetween membranes 712, a second rigid mount arranged to protrude from abottom of housing 704 and further arranged to protrude from a first sideof housing 704 (e.g., from a first bottom corner of housing 704), and athird rigid mount arranged to protrude from a bottom of housing 704 andfurther arranged to protrude from a second side of housing 704 (e.g.,from a second bottom corner of housing 704).

Housing 704 is comprised of gasket groove 716 in which gasket 718 isarranged to create a seal between housing 704 and a surface of a batterypack sidewall in which housing 704 is installed or embedded. Gasket 718is comprised of gasket protrusions 720, which are structured to securegasket 718 in gasket groove 716 by increasing friction between gasket718 and gasket groove 716. Gasket 718 encircles membranes 712, which aresupported by deformable struts 722. Gasket 718 extends partially outgasket groove 716 such that when rigid mounts 708 are secured to amounting sidewall, gasket 718 is partially compressed against themounting sidewall and acts as a seal to prevent hot or pressurize fluidfrom passing between the mounting sidewall and housing 704. Gasketgroove 716 may further comprise a pair of recesses between membranes 712configured to accommodate gasket protrusions 720. Gasket 718 maycomprise a plurality of additional protrusions structured to match aprofile of gasket groove 716 in housing 704 such that gasket 718 remainsin a secured position and maintains a continuous seal encircling both ofmembranes 712. Deformable struts 722 are configured to mechanicallydeform and release membranes 712 (e.g., the membranes are displaced orfall out of their respective housings) when exposed to thermal runawayconditions, thereby creating openings in housing 704 where membranes 712are depicted in FIGS. 7A and 7B. The housing may comprise three rigidmounts as shown.

FIG. 8A depicts outer surface 802A of pressure release valve 800 andFIG. 8B depicts inner surface 802B of pressure release valve 800, inaccordance with some embodiments of the disclosure. Pressure releasevalve 800 may comprise more or fewer than the components or featuresdepicted in FIGS. 8A and 8B. Pressure release valve 800 may beincorporated into or may incorporate any or all of the components orfeatures depicted in or described in reference to FIGS. 1-7B and 9A-13 .Additionally, pressure release valve 800 may be assembled, developed, ormanufactured based at least in part on any of the steps depicted in ordescribed in reference to FIG. 14 .

Pressure release valve 800 comprises extended membrane 804, whichcomprises an area which avoids a need to include a second membrane, inaccordance with some embodiments of the present disclosure. Pressurerelease valve 800 is comprised of deformable struts 806 (e.g., as shownin FIG. 8B), rigid mounts 706 (e.g., configured to receive rigid insertsand comprised of reinforcement vanes as shown in FIG. 7 ), and gasketgroove 716 configured to receive a sealing gasket. Additionally, housing708 comprises at least one of stiffening extension 810 such that housing708 corresponds to a material stiffness that does not compromise orcreate a weak point in a sidewall in which pressure release valve 800may be installed.

The pressure release valves shown in FIGS. 7A-8B may be incorporatedinto a battery pack. The battery pack may comprise elements and theassemblies depicted in any or all of FIGS. 1-13 . The battery pack maycomprise at least one sidewall, wherein the sidewall is arranged to forman enclosure at least partially around a battery module, and wherein theat least one sidewall comprises at least one outlet. The battery modulemay be positioned laterally proximate to the at least one sidewall,wherein the battery module comprises a plurality of battery cells. Thepressure release valves of FIGS. 7A-8B may comprise at least one ventingstructure (e.g., membranes 712 or 804), wherein the at least one ventingstructure is fixedly attached to the at least one outlet. The at leastone venting structure may comprise a housing configured to be secured tothe at least one sidewall, a first membrane positioned towards a firstside of the housing, a second membrane positioned adjacent to the firstmembrane and positioned towards a second side of the housing, and agasket structured to form a continuous seal between the housing and thesidewall.

FIG. 9A depicts battery pack 900 comprised of sidewall 902 with externalsurface 904, in accordance with some embodiments of the disclosure. FIG.9B depicts inner surface 906 of sidewall 902, in accordance with someembodiments of the disclosure. Battery pack 900 may comprise more orfewer than the components or features depicted in FIGS. 9A and 9B.Battery pack 900 may be incorporated into or may incorporate any or allof the components or features depicted in or described in reference toFIGS. 1A-8B and 10A-13 . Additionally, battery pack 900 may beassembled, developed, or manufactured based at least in part on any ofthe steps depicted in or described in reference to FIG. 14 .

Sidewall 902 is shown with dual membrane pressure release valvesembedded in external surface 904, in accordance with some embodiments ofthe present disclosure. Sidewall 902 comprises top lateral edge 912.Dual membrane valves 700 are arranged in positions configured optimizethe egress of at least one of pressurized or heated fluid from insidebattery pack 900. Each of dual membrane pressure release valves 700 isdepicted as being rotated or moved towards the center of externalsurface 904 (e.g., at the depicted angle a or along the trajectoriesillustrated by the arrows), depending on where vehicle components aroundbattery pack 900 are arranged or where the optimal egress position forthe fluid is, considering the arrangement of battery cells or batterymodules and other components inside battery pack 900 and surroundingstructures. In some embodiments, single membrane pressure release valve908 is embedded in angled sidewall 910, which is fixedly attached toexternal surface 904 of sidewall 902 to at least partially form at leastone enclosure for battery cells (e.g., module bays 105 of FIG. 1 ). Anadditional single membrane pressure release valve (not shown) may alsobe embedded in an angled sidewall fixedly attached on an opposite sideof external surface 904 of sidewall 902 to balance the release of atleast one of pressurize or heated fluid across sidewall 902. Thecumulative area of single membrane pressure release valve 908 and dualmembrane pressure release valves 700 may equal or correspond to thecumulative area of pressure release valves installed in a rear-facingsidewall of the battery assembly. For example, there may be up to a 5%difference in area between the cumulative area of single membranepressure release valve 908 and the cumulative area of dual membranepressure release valves 700. In some embodiments, the vehicle assemblymay result in a functional need for either sidewall 902 or a rear-facingsidewall arranged to face opposite of external surface 904 to serve as aprimary egress opening for at least one of pressurized or heated fluid,depending on which sidewalls are arranged to have outlets which aredirected towards target expulsion area 402 of FIG. 4 . Dual membranepressure release valves 700 are optimally positioned on external surface904 such that the stiffness of sidewall 902 maintains a target stiffness(e.g., near the vertical center of sidewall 902).

FIGS. 10A, 10B, and 10C each depict battery pack 100 with dual membranepressure release valves 700 embedded in a sidewall, in accordance withsome embodiments of the disclosure. Battery pack 100 may comprise moreor fewer than the components or features depicted in FIGS. 10A, 10B, and10C. Battery pack 100 may be incorporated into or may incorporate any orall of the components or features depicted in or described in referenceto FIGS. 1A-9B and 11A-13 . Additionally, battery pack 100 may beassembled, developed, or manufactured based at least in part on any ofthe steps depicted in or described in reference to FIG. 14 .

As shown in FIG. 10A, dual membrane pressure release valves 700 arepositioned such that when the pressure release valves enable the egressof at least one of pressurized or heated fluid from within battery pack100, the trajectory of the expelled fluid does not get influenced ormodified by the depicted features surrounding battery pack 100.Additionally, the positioning of dual membrane pressure release valves700 is influenced by impact area 1002. Impact area 1002 corresponds to aportion of the external surface of battery pack 100 that is structuredto receive impacts of surrounding components in response to a vehicleimpact event or other related event (e.g., an event where a rapiddeceleration occurs resulting in the deformation of vehicle componentssurrounding battery pack 100). Dual membrane pressure release valves 700are arranged such that the target stiffness of the sidewall of batterypack 100 is not compromised by the presence of the pressure releasevalve and neither of dual membrane pressure release valves 700 issubjected to a direct component impact in the aforementioned event orevents. As shown in FIGS. 10A, 10B and 10C, dual membrane pressurerelease valves 700 are mounted with their inboard sides rotated upwards(e.g., at least one rigid mount is arranged closer to a top lateral edgeof a sidewall of battery pack 100 than at least one other rigid mount),which raises the lowest point (e.g., the lowest rigid mount) of thepressure release valves. In some embodiments, the lowest point of thepressure release valves is raised to provide clearance between an edgeof either of dual membrane pressure release valves 700 or the outermostedge of impact area 1002.

In FIG. 10B, vehicle component profile 1004A is positioned relativelyclose to a periphery of sidewalls forming battery pack 100. There may beadditional clearance between the forward-facing portion of battery pack100 and vehicle component profile 1004A to ensure impact area 1002 isnot subjected to unexpected impacts from surrounding components.Accordingly, the location of dual membrane pressure release valves 700on the forward-facing portion of the sidewall enables expelled fluid tosubstantially avoid vehicle component profile 1004A. In FIG. 10C,vehicle component profile 1004B extends forwards from underneath a frontsidewall of battery pack 100 (e.g., a z-bracket that provides supportfor the front of the battery assembly). Vehicle component profile 1004Bis centered with respect to battery pack 100 and the lateral locationsof dual membrane pressure release valves 700 are selected such thatexpelled hot gas substantially avoids the component occupying a spacesubstantially similar to vehicle component profile 1004B.

FIGS. 11A and 11B depict a pair of views of battery pack 100 of FIG. 1 ,in accordance with some embodiments of the disclosure. Battery pack 100may comprise more or fewer than the components or features depicted inFIGS. 11A and 11B. Battery pack 100 may be incorporated into or mayincorporate any or all of the components or features depicted in ordescribed in reference to FIGS. 1A-10C, 12, and 13 . Additionally,battery pack 100 may be assembled, developed, or manufactured based atleast in part on any of the steps depicted in or described in referenceto FIG. 14 .

Multidirectional vent passages 118 remain generally unobstructed bycomponents of battery pack 100, and as a result freely permit fluidexchanges between adjacent bays 105 of the battery pack 100 at leastalong floor structure 114. Additional nominal fluid exchange betweenbays 105 may nevertheless occur via other pathways within battery pack100. For example, coolant passages extend in a longitudinal directionthrough battery pack 100, extending through corresponding crossmemberapertures 134 of one or more of crossmember(s) 106. Crossmemberapertures 134 may generally fit closely around coolant passages 132,permitting a nominal amount of fluid exchange between adjacent bays 105.Further, a tunnel structure of battery pack 100 may extendlongitudinally along a lateral center of battery pack 100, resulting inadditional nominal pathways for fluid exchange between bays 105 (e.g.,over a top part of the crossmembers 106 along cover 116 which is notshown in FIGS. 11A and 11B). In contrast to these pathways for nominalfluid exchange between bays 105, multidirectional vent passages 118provide a relatively unobstructed and direct path for fluid exchangebetween bays 105. Additionally, to the extent modules 104 may havebatteries/cells venting downward toward floor structure 114,multidirectional vent passages 118 provide a direct path between bays105 coinciding with the direction of venting of these module(s) 104.

The bidirectional vent passages may have any shape or configuration thatis convenient. Multidirectional vent passages 118 may be positioned at alower portion of each of bays 105, adjacent floor structure 114 ofbattery pack 100. Multidirectional vent passage 118 may be relativelywider along floor structure 114 (e.g., having a width at least twice asgreat as a height thereof). One or more of the bays 105, or even each ofbays 105 of battery pack 100, may include two or more adjacent batterymodules 104, with crossmembers 106 on either side of modules 104defining respective multidirectional vent passages 118. Any number ofcrossmembers 106 may be employed, defining any number of bays 105, asnoted above. Multidirectional vent passages 118 of crossmembers 106 areeach aligned longitudinally, thereby providing a straight andunobstructed flow path between each of bays 105. Additionally, thebattery modules 104 within one or more of the bays, or within each bay105 of battery pack 100, may be installed within battery pack 100 suchthat modules 104 are raised above floor structure 114, thereby allowingfluid flow within each bay 105 along floor structure 114 beneath batterymodules 104.

The restricted flow paths to a number of pressure release valves 108 atthe front and rear locations may facilitate venting from battery pack100 at desired locations (e.g., with respect to a vehicle in whichbattery pack 100 is installed). For example, the locations of pressurerelease valves 108 may correspond to locations of the vehicle where aflow of heat or pressure may be relatively unnoticed by passengers, orotherwise may not impact vehicle systems. In some embodiments, at leastone pressure release valve is embedded in a first sidewall positioned ina first portion of a vehicle comprised of battery pack 100, wherein thefirst portion may be a front portion. In some embodiments, at least onepressure release valve is embedded in a second sidewall positioned in asecond portion of the vehicle, wherein the second portion may be a rearportion. Either the first or the second portion may be either a front ora rear portion. By way of example, rearward pressure release valves 108may vent to an area outer to the vehicle and beneath the vehicle, near afront or rear cargo area, cargo box, or the like. Accordingly,passengers exiting the vehicle or standing near the vehicle may beunlikely to notice the venting. Focusing the venting locations to thefront and rear of battery pack 100 may also facilitate redirection of avent flow or heat to areas of the vehicle away fromtemperature-sensitive areas or materials. In some examples, the vehiclemay have deflectors or other devices for redirecting vent flow form thebattery pack 100.

The restricted flow paths for venting battery pack 100 may alsofacilitate consistent venting of valves 108 at a desired pressure level.More particularly, relatively larger vents may typically be moredifficult to control with respect to providing consistent venting at adesired pressure level. For example, for larger pressure release valvestructures it may be difficult to achieve a sufficient preload that willpermit venting at the appropriate internal pressure, prevent venting atlower pressures where venting is not necessary, and also sufficientlyseal against external contaminants such as water. Accordingly, in theexample illustrations shown, there are multiple pressure release valves108 along the front and rear venting locations. As a result, thepressure release valves 108, and in particular moveable umbrellastructures 109 are each relatively small and thus may more consistentlyprovide venting at a desired pressure. As noted above, pressure releasevalves 108 may be configured to vent in response to an internal pressureof 5 kPa.

FIG. 11B depicts battery pack 100 comprising module bays 105 formed bycrossmembers 106, each comprising gas egress openings in accordance withsome embodiments of the present disclosure. Also depicted is rear-facingsidewall 102 b comprising a plurality of dual membrane pressure releasevalves 108. Dual membrane pressure release valves 108 are embedded inthe rear-facing sidewall 102 b and may be laterally aligned. In someembodiments, three pressure release valves comprise the plurality ofpressure release valves. Each of the three pressure release valves aredistanced by an equal amount from each other and arranged to enable theegress of at least one of pressurize or heated fluid from inside modulebays 105 such that the egress results in fluid trajectories that guidethe fluid around critical vehicle components. In some embodiments rearfacing sidewall 102 b may comprise one or more guiding ribs, asdescribed above, to modify the exit trajectory of gas that enterssidewalls 102 and passes through dual membrane pressure release valves108. Rear facing dual membrane pressure release valves 108 may beconfigured to complement at least one pressure release valve embedded inforward-facing sidewall 102 a, which is arranged at an opposite end ofbattery pack 100. The cumulative area of the pressure release valves maycorrespond with target gas egress rates and a target gas egressdirection (e.g., towards the forward -facing sidewall or towards therear-facing sidewall to avoid venting gas in the direction of criticalvehicle components or occupant arears).

FIG. 12 depicts battery pack 1200, in accordance with some embodimentsof this disclosure. Battery pack 1200 may comprise more or fewer thanthe components or features depicted in FIG. 12 . Battery pack 1200 maybe incorporated into or may incorporate any or all of the components orfeatures depicted in or described in reference to FIGS. 1A-11B and 13 .Additionally, battery pack 1200 may be assembled, developed, ormanufactured based at least in part on any of the steps depicted in ordescribed in reference to FIG. 14 .

Battery pack 1200 is comprised of sidewall 102D of FIG. 1 , and angledsidewall 1202 (e.g., angled at angle α relative to a plane defined byforward-facing sidewall 102A that enables the egress of gas away fromcritical vehicle components), which at least partially form a pluralityof battery cell enclosures (e.g., module bays 105 of FIG. 1 ). Singlemembrane pressure release valves 1204 may be installed in each of singlemembrane pressure release valve outlets 1206. In some embodiments, thereis at least one single membrane pressure release valve per sidewall perbattery cell enclosure. In some embodiments, valve outlets 1206 are notpresent (e.g., having less than four present or zero) along the sides ofbattery pack 1200 as the venting enabled by forward-facing sidewallpressure release valves 1208 and rear-facing sidewall pressure releasevalves 1210 enable adequate venting of battery pack 1200. In someembodiments, dual membrane pressure release valves may be utilized,depending on target gas egress rates balances against moisture sealingrequirements and sidewall stiffness requirements. Also depicted areforward-facing sidewall pressure release valves 1208 and rear-facingsidewall pressure release valves 1210. Each of the forward andrear-facing pressure release valves are configured to complement thepressure release valves of the opposite facing sidewall. The cumulativearea of the pressure release valves may correspond with target gasegress rates and a target gas egress direction (e.g., towards theforward -facing sidewall or towards the rear-facing sidewall to avoidventing gas in the direction of critical vehicle components or occupantarears).

FIG. 13 shows battery pack 1300, in accordance with some embodiments ofthe disclosure. Battery pack 1300 may comprise more or fewer than thecomponents or features depicted in FIG. 13 . Battery pack 1300 may beincorporated into or may incorporate any or all of the components orfeatures depicted in or described in reference to FIGS. 1A-12 .Additionally, battery pack 1300 may be assembled, developed, ormanufactured based at least in part on any of the steps depicted in ordescribed in reference to FIG. 14 .

FIG. 13 shows a cross section of battery pack 1300 which enables themerging of fluid trajectories 1310 characterized by the arrows betweenbattery modules 104, based on the battery assembly configuration whichas shown may include vertically stacked battery modules, to definetarget outlet location 1302 in a sidewall at least partially defining abattery enclosure (e.g., module bays 105). Target outlet location 1302is configured to be at a heigh in sidewall 102 corresponding to amaximum flow rate. For example, target outlet location 1302 may be at aheight on sidewall 102 that is between 20% and 80% of the overall heightof sidewall 102. Battery pack 1300 comprises battery pack cover 1304 andbattery pack base 1306 fixedly attached to at least one of enclosurecrossmember 106 and at least one of sidewall 102. Crossmember 106 maycomprise gas egress opening 1308 corresponding to a fluid flowtrajectory that contributes to fluid trajectories 1310. Sidewall 102 maycomprise a venting structure at an optimal height corresponding totarget outlet location 1302. The venting structure may comprise aplurality of pressure release valves (e.g., two pressure release valvesangled on a forward-facing end sidewall, or three pressure releasevalves laterally aligned on a rear-facing end sidewall). The cumulativearea of the pressure release valves may correspond with target gasegress rates and a target gas egress direction (e.g., towards theforward-facing sidewall or towards the rear-facing sidewall to avoidventing gas in the direction of critical vehicle components or occupantarears). The venting structure may be positioned in sidewall 102 at anoptimal height based on fluid trajectories 1310. Fluid trajectories 1310may correspond at least one of hot or pressurized fluid generated by theoperation of the depicted battery modules 104 separated by crossmember106. Battery pack 1300 may further comprise at least one of mica barrier1312 positioned above each of a plurality of enclosures formed at leastpartially by sidewall 102 and crossmember 106 between battery pack cover1304 and battery pack base 1306. Battery pack cover 1304 and batterypack base 1306 may be fixedly attached to a base of sidewall 102 (e.g.,a forward-facing sidewall and or a rear-facing sidewall). Batterymodules 104 arranged on top of the other modules may be positioned suchthat pressurized or heated fluid vents upward towards battery pack cover1304 while the lower layer of modules 104 may be positioned to ventdownwardly toward battery pack base 1306.

FIG. 14 is a flowchart of method 1400 for at least one of manufacturingor venting a battery assembly (e.g., battery pack 100 of FIG. 1 ), inaccordance with some embodiments of the disclosure. Method 1400 maycomprise more or fewer than the steps depicted in FIG. 14 . Method 1400may be incorporated into the development, assembly, manufacturing, orventing of any or all of the components or features depicted in ordescribed in reference to FIGS. 1A-13 . Process blocks depicted withdashed borders comprise steps that are optional in developing,assembling, manufacturing, or venting battery pack 100 of FIG. 1 .

At 1402, at least one sidewall comprising an inner wall, an outer wall,and at least one guiding rib is provided, wherein the at least oneguiding rib comprises a first end that abuts the inner wall, a secondend that abuts the outer wall, a profile structured to modify thetrajectory of gas generated from inside the battery assembly. In someembodiments at 1402A, providing at least one sidewall comprisesextruding a rigid material to form the at least one sidewall. In someembodiments, method 1400 further comprises machining, at 1402B, an inletopening in the inner wall to expose a first side of the guiding rib. Insome embodiments, at 1402C, an outlet opening is machined in the outerwall to expose a second side of the guiding rib, wherein machining thesecond opening comprises machining an accommodating recess for a ventstructure. At 1404, the at least one sidewall is arranged to form anenclosure at least partially. At 1406, a battery module is arrangedinside the enclosure, wherein the battery module comprises a pluralityof battery cells. In some embodiments, at 1408, the vent structure ismounted to the outer wall such that the vent structure is aligned withthe outlet opening.

In some embodiments, the battery assemblies described herein comprisesidewalls manufactured by a particular method. For example, a rigidmaterial (e.g., aluminum), may be extruded into a shape that comprisesat least one guiding rib. The guiding rib may comprises a profilecorresponding to a target gas trajectory and wherein the at least oneguiding rib interfaces with a first side of the extruded rigid materialat a first location on the first side which is higher than where theguiding rib interfaces with a second side of the extruded rigidmaterial. A first opening may be machined (e.g., milled or drilled) inthe first side of the extruded rigid material to expose a first side ofthe guiding rib, wherein the first opening is positioned higher than asecond opening in a second side. A second opening may also be machined(e.g., milled or drilled) in the second side of the extruded rigidmaterial to expose a second side of the guiding rib, wherein machiningthe second opening comprises machining an accommodating recess for avent structure. A vent structure may then be mounted to the second sideof the sidewall. such that the vent structure is aligned with the secondopening;

In some embodiments, the battery packs described herein may have ventingstructures or pressure release valves positioned in the sidewalls of thebattery packs by a particular method of manufacture. A frame assemblymay be provided for the battery pack. The frame assembly may comprise aplurality of sidewalls, wherein the plurality of sidewalls furthercomprises at least a forward-facing sidewall and a rear-facing sidewall.At least one of the battery pack or the frame assembly may comprise anynumber of additional components described herein or shown in FIGS. 1A-13. A first plurality of pressure release valves may be mounted on theforward-facing sidewall and a second plurality of pressure releasevalves may be mounted to the rear-facing sidewall. The pressure releasevalves may be two membrane pressure release valves, single membranepressure release valves, and any combination thereof. The cumulativearea of the pressure release valves may correspond with target gasegress rates and a target gas egress direction (e.g., towards theforward -facing sidewall or towards the rear-facing sidewall to avoidventing gas in the direction of critical vehicle components or occupantarears). Features of the various example battery packs herein maygenerally be combined without limitation, absent express statementsherein to the contrary.

The foregoing is merely illustrative of the principles of thisdisclosure, and various modifications may be made by those skilled inthe art without departing from the scope of this disclosure. Theabove-described embodiments are presented for purposes of illustrationand not of limitation. The present disclosure also can take many formsother than those explicitly described herein. Accordingly, it isemphasized that this disclosure is not limited to the explicitlydisclosed methods, systems, and apparatuses, but is intended to includevariations to and modifications thereof, which are within the spirit ofthe following paragraphs.

While some portions of this disclosure may refer to examples, any suchreference is merely to provide context to the instant disclosure anddoes not form any admission as to what constitutes the state of the art.

What is claimed is:
 1. A battery pack for an electric vehicle,comprising: a pack housing comprising a crossmember, wherein: thecrossmember comprises a multidirectional vent passage configured toallow venting with a first bay and a second bay; and a pressure releasevalve arranged with the pack housing and configured to release pressurebased on the multidirectional vent passage.
 2. The battery pack of claim1, wherein the multidirectional vent passage is configured to modify afirst pressure with the first bay and a second pressure with the secondbay.
 3. The battery pack of claim 1, wherein the pressure release valveis a one-way pressure release valve to release pressure based at leaston the venting through the multidirectional vent passage.
 4. The batterypack of claim 1, further comprising a plug pressure release valve and adeformable pressure release valve, wherein the plug pressure releasevalve is configured to permit the venting with the first and second baysin response to a difference between a first internal pack pressure andan external pressure.
 5. The battery pack of claim 4, wherein: thedifference between the first internal pack pressure and the externalpressure is a first pressure differential; the plug pressure releasevalve is configured to permit venting in response to being exposed tothe first pressure differential; the deformable pressure release valveis configured to permit venting in response to being exposed to a secondpressure differential greater than the first pressure differential; andthe pressure release valve is configured to permit venting in responseto a third pressure differential that is less than the second pressuredifferential and greater than the first pressure differential.
 6. Thebattery pack of claim 1, further comprising a deformable pressurerelease valve configured to permit the venting with the first and secondbays in response to a second internal pack pressure meeting a thresholdpressure.
 7. The battery pack of claim 1, further comprising adeformable pressure release valve, wherein the deformable pressurerelease valve comprises a structure configured to deform in response toat least one of pressurized or heated fluid within the battery pack. 8.The battery pack of claim 1, wherein the pressure release valvecomprises an actuatable membrane pressure release valve structure, anumbrella valve or combinations thereof.
 9. The battery pack of claim 1,wherein the pressure release valve comprises at least one openingcovered by a membrane, a moveable cover, or a rotating enclosuresurface, or combinations thereof, that is configured to release orequalize pressure when arranged such that the at least one opening isuncovered.
 10. The battery pack of claim 1, wherein: themultidirectional vent passage is positioned at a lower portion of thefirst and second bays above a floor surface of the battery pack; themultidirectional vent passage has a width at least twice as great as aheight of the multidirectional vent passage; the lower portion of thefirst and second bays comprises a lower portion of the crossmemberdefining the first and second bays; and at least one of the first andsecond bays comprises at least one battery and at least one crossmembercomprised of a second multidirectional vent passage.
 11. The batterypack of claim 1, wherein the battery pack includes at least twocrossmembers defining in part at least three bays, each of thecrossmembers comprising respective multidirectional vent passages. 12.The battery pack of claim 1, wherein each bay of the battery packcomprises two batteries raised above a floor structure of the batterypack, thereby allowing fluid flow within each bay along the floorstructure beneath the two batteries.
 13. The battery pack of claim 12,wherein allowing fluid flow comprises enabling unrestricted trajectoriesof fluid to propagate between bays through multidirectional ventpassages.
 14. The battery pack of claim 1, wherein at least one singlemembrane venting structure is embedded in a first end of the batterypack and at least one dual membrane venting structure is embedded in asecond end of the battery pack.
 15. A battery pack for an electricvehicle, comprising: a pack enclosure comprising a crossmember that atleast partially forms at least two adjacent bays, wherein: thecrossmember comprises a multidirectional vent passage configured tomodify pressure between a first bay and a second bay; and a one-waypressure release valve positioned with the pack enclosure, whereinpressure is modified based on the multidirectional vent passage and theone-way pressure release valve of the battery pack.
 16. The battery packof claim 15, further comprising a plug pressure release valve and adeformable pressure release valve; wherein the plug pressure releasevalve is configured to permit the venting with the first and second baysin response to a first internal pack pressure below a first thresholdpressure; and wherein the deformable pressure release valve isconfigured to permit the venting with the first and second bays inresponse to a second internal pack pressure exceeding a second thresholdpressure greater than the first threshold pressure.
 17. The battery packof claim 15, wherein the pressure release valve comprises at least oneopening covered by a membrane, a moveable cover, or a rotating enclosuresurface or combinations thereof that is configured to release orequalize pressure when arranged such that the at least one opening isuncovered.
 18. A method for venting a battery pack, the methodcomprising: constructing a plurality of bays each with a respectivecrossmember using at least two sidewalls, wherein each respectivecrossmember comprises a multidirectional vent passage configured tomodify pressure in a first bay and a second bay of the plurality ofbays; and providing a pressure release valve with a pack housing suchthat the pressure is modified based at least on the multidirectionalvent passage and the pressure release valve.
 19. The method of claim 18,further comprising: forming the plurality of bays by arranging at leasta first wall and a second wall such that a top edge of the first walland the second wall are laterally aligned or parallel, wherein a firstend of the crossmember is fixedly attached to the first wall and asecond end of the crossmember, opposite the first end, is fixedlyattached to the second wall; arranging a first battery, comprising atleast one battery cell, in the first bay; and arranging a secondbattery, comprising at least one battery cell, in the second bay. 20.The method of claim 19, further comprising: forming at least one firstguiding rib in an extruded material comprising the first wall whereinthe at least one first guiding rib connects an opening on an innersurface of the first wall to an opening on an outer surface of the firstwall; forming at least one second guiding rib in an extruded materialcomprising the second wall wherein the at least one second guiding ribconnects an opening on an inner surface of the second wall to an openingon an outer surface of the second wall; and machining an opening in eachof the outer surface of the first wall and the outer surface of thesecond wall, wherein each of the openings comprises a correspondingfeature configured to receive at least one mounting extension of thepressure release valve.